Lightning protection for power circuits has normally been provided with a high voltage breakdown device included in a series circuit connected across two current carrying leads supplying power input to the power circuit. The breakdown devices may include various semiconductor devices either singly or in combination including voltage clamping devices, metal oxide varistors and bidirectional zener diodes or such other devices such as gas discharge tubes. The Y-capacitor is a specially constructed capacitor whose construction allows the capacitor to withstand the stress of high voltage transient pulses. Y-capacitors are often connected between the input line and frame ground for the purpose of EMI suppression.